Minor fixes

b_asic/sfg_generators.py

@@ -60,6 +60,9 @@ def wdf_allpass(
         Signal flow graph
     """
     np_coefficients = np.squeeze(np.asarray(coefficients))
+    order = len(np_coefficients)
+    if not order:
+        raise ValueError("Coefficients cannot be empty")
     if not np_coefficients:
         raise ValueError("Coefficients cannot be empty")
     if np_coefficients.ndim != 1:
@@ -70,7 +73,6 @@ def wdf_allpass(
         output = Output()
     if name is None:
         name = "WDF allpass section"
-    order = len(np_coefficients)
     odd_order = order % 2
     if odd_order:
         # First-order section
@@ -164,7 +166,8 @@ def direct_form_fir(
     transposed_direct_form_fir
     """
     np_coefficients = np.squeeze(np.asarray(coefficients))
-    if not np_coefficients:
+    taps = len(np_coefficients)
+    if not taps:
         raise ValueError("Coefficients cannot be empty")
     if np_coefficients.ndim != 1:
         raise TypeError("coefficients must be a 1D-array")
@@ -179,7 +182,6 @@ def direct_form_fir(
     if add_properties is None:
         add_properties = {}
 
-    taps = len(np_coefficients)
     prev_delay = input_op
     prev_add = None
     for i, coeff in enumerate(np_coefficients):
@@ -244,7 +246,8 @@ def transposed_direct_form_fir(
     direct_form_fir
     """
     np_coefficients = np.squeeze(np.asarray(coefficients))
-    if not np_coefficients:
+    taps = len(np_coefficients)
+    if not taps:
         raise ValueError("Coefficients cannot be empty")
     if np_coefficients.ndim != 1:
         raise TypeError("coefficients must be a 1D-array")
@@ -259,7 +262,6 @@ def transposed_direct_form_fir(
     if add_properties is None:
         add_properties = {}
 
-    taps = len(np_coefficients)
     prev_delay = None
     for i, coeff in enumerate(reversed(np_coefficients)):
         tmp_mul = ConstantMultiplication(coeff, input_op, **mult_properties)